Add config key to dump shaders in local directory (#265)

* Add config key to dump shaders in local directory

* Address feedback

Ryujinx.Graphics/Gal/ShaderDumper.cs

@@ -0,0 +1,96 @@
+using System;
+using System.IO;
+
+namespace Ryujinx.Graphics.Gal
+{
+    static class ShaderDumper
+    {
+        private static string RuntimeDir;
+
+        private static int DumpIndex = 1;
+
+        public static void Dump(IGalMemory Memory, long Position, GalShaderType Type, string ExtSuffix = "")
+        {
+            if (string.IsNullOrWhiteSpace(GraphicsConfig.ShadersDumpPath))
+            {
+                return;
+            }
+
+            string FileName = "Shader" + DumpIndex.ToString("d4") + "." + ShaderExtension(Type) + ExtSuffix + ".bin";
+
+            string FilePath = Path.Combine(DumpDir(), FileName);
+
+            DumpIndex++;
+
+            using (FileStream Output = File.Create(FilePath))
+            using (BinaryWriter Writer = new BinaryWriter(Output))
+            {
+                long Offset = 0;
+
+                ulong Instruction = 0;
+
+                //Dump until a NOP instruction is found
+                while ((Instruction >> 52 & 0xfff8) != 0x50b0)
+                {
+                    uint Word0 = (uint)Memory.ReadInt32(Position + Offset + 0);
+                    uint Word1 = (uint)Memory.ReadInt32(Position + Offset + 4);
+
+                    Instruction = Word0 | (ulong)Word1 << 32;
+
+                    //Zero instructions (other kind of NOP) stop immediatly,
+                    //this is to avoid two rows of zeroes
+                    if (Instruction == 0)
+                    {
+                        break;
+                    }
+
+                    Writer.Write(Instruction);
+
+                    Offset += 8;
+                }
+
+                //Align to meet nvdisasm requeriments
+                while (Offset % 0x20 != 0)
+                {
+                    Writer.Write(0);
+
+                    Offset += 4;
+                }
+            }
+        }
+
+        private static string DumpDir()
+        {
+            if (string.IsNullOrEmpty(RuntimeDir))
+            {
+                int Index = 1;
+
+                do
+                {
+                    RuntimeDir = Path.Combine(GraphicsConfig.ShadersDumpPath, "Dumps" + Index.ToString("d2"));
+
+                    Index++;
+                }
+                while (Directory.Exists(RuntimeDir));
+
+                Directory.CreateDirectory(RuntimeDir);
+            }
+
+            return RuntimeDir;
+        }
+
+        private static string ShaderExtension(GalShaderType Type)
+        {
+            switch (Type)
+            {
+                case GalShaderType.Vertex:         return "vert";
+                case GalShaderType.TessControl:    return "tesc";
+                case GalShaderType.TessEvaluation: return "tese";
+                case GalShaderType.Geometry:       return "geom";
+                case GalShaderType.Fragment:       return "frag";
+
+                default: throw new ArgumentException(nameof(Type));
+            }
+        }
+    }
+}